Method for manufacturing 2-Chloro-1, 1-difluoroethane (HCFC-142), 1,1,2-trifluoroethane (HFC-143), and (E)-1,2-difluoroethylene (HFO-1132(E)) and/or (Z)-1,2-difluoroethylene (HFO-1132(Z))

The present disclosure relate to a method for producing 2-chloro-1,1-difluoroethane (HCFC-142), 1,1,2-trifluoroethane (HFC-143), and (E)-1,2-difluoroethylene (HFO-1132(E)) and/or (Z)-1,2-difluoroethylene (HFO-1132(Z)).

Various conventional methods have been proposed for the production of fluoroethane, such as HCFC-142.

Patent Literature 1 discloses a method for producing HCFC-142 from 1,1,2-trichloroethane (HCC-140) and/or 1,2-dichloroethylene (HCO-1130).

Patent Literature 2 discloses a heat transfer composition containing an iodocarbon and a diene-based compound for stabilizing the decomposition of the iodocarbon.

The present disclosure includes the following aspects.

Item 1

A method for producing 2-chloro-1,1-difluoroethane (HCFC-142) comprising

bringing at least one chlorine-containing compound selected from the group consisting of 1,1,2-trichloroethane (HCC-140), (E)-1,2-dichloroethylene (HCO-1130(E)), (Z)-1,2-dichloroethylene (HCO-1130(Z)), 1,2-dichloro-1-fluoroethane (HCFC-141), (E)-1-cloro-2 fluoroethylene (HCFO-1131 (E)) and (Z)-1-chloro-2-fluoroethylene (HCFO-1131(Z)) into contact with hydrogen fluoride in the presence of a stabilizer to perform at least one fluorination reaction, thus obtaining a reaction gas containing HCFC-142 hydrogen chloride, and hydrogen fluoride.

In the present specification, terms are abbreviated as follows.

In the present disclosure, the pressure is gauge pressure unless indicated otherwise.

According to the method for producing HCFC-142 of the present disclosure, the decomposition of a starting material, such as HCC-140 and HCO-1130, is suppressed, thus producing HFC-142 with high yield and high efficiency.

It is known that HCC-140 (CHClCHCl) and HCO-1130 (E/Z) (CHCl═CHCl), which are starting materials for the production of HCFC-142, easily decompose, and the decomposition causes hydrogen chloride (HCl) to generate. For this reason, care must be taken in handling starting materials of HCC-140 and HCO-1130 (E/Z).

The present inventors have found that the decomposition of such HCC-140, HCO-1130 (E/Z), and the like affects conversion and selectivity in the production of HCFC-142.

The method for producing 2-chloro-1,1-difluoroethane (HCFC-142) of the present disclosure comprises bringing at least one chlorine-containing compound selected from the group consisting of 1,1,2-trichloroethane (HCC-140), (E)-1,2-dichloroethylene (HCO-1130(E)), (Z)-1,2-dichloroethylene (HCO-1130(Z)), 1,2-dichloro-1-fluoroethane (HCFC-141), (E)-1-chloro-2-fluoroethylene (HCFO-1131(E)), and (Z)-1-chloro-2-fluoroethylene (HCFO-1131(Z)) into contact with hydrogen fluoride in the presence of a stabilizer to perform at least one fluorination reaction, thus obtaining a reaction gas containing HCFC-142, hydrogen chloride, and hydrogen fluoride.

The method for producing HCFC-142 of the present disclosure having the above feature prevents the decomposition of starting materials, such as HCC-140 and HCO-1130, extends the catalyst life when a catalyst is used, and prevents the formation of by-products, thus producing HCFC-142 with high yield and high efficiency.

(1) Starting Material Compound

In the production method of the present disclosure, at least one chlorine-containing compound selected from the grout consisting of HCC-140, HCO-1130 (E/Z), HCFC-141, and HCFO-1131 (E/Z) is used as a starting material compound.

“(E/Z)” above means that the E (trans) and/or Z (cis) bodies are included.

All of these chlorine-containing compounds are available at low cost, which can reduce the costs for the HCFC-142 production method.

Among these chlorine-containing compounds, the chlorine-containing compound is preferably HCC-140 or HCO-1130 (E/Z), or both, and more preferably HCO-1130 (E/Z), from the viewpoint of the costs for the starting material.

(2) Stabilizer

In the production method of the present disclosure, the chlorine-containing compound described above is brought into contact with hydrogen fluoride in the presence of a stabilizer. The use or the stabilizer prevents the decomposition of chlorine-containing compounds, such as HCC-140 and HCO-1130 (E/Z), which are starting materials, extends the catalyst life when a catalyst is used, and suppresses the generation of by-products, which allows the production of HCFC-142 with nigh efficiency and high yield.

As the stabilizer, at least one stabilizer selected from the group consisting of hydroquinone stabilizers, unsaturated alcohol stabilizers, nitro stabilizers, amine stabilizers, phenol stabilizers, epoxy stabilizers, and other stabilizers can be preferably used.

As a hydroquinone stabilizer, at least one hydroquinone stabilizer selected from the group consisting of hydroquinone monomethyl ether (MEHQ), methoxyhydroquinone, and methylhydroquinone can be preferably used.

As an unsaturated alcohol stabilizer, at least one unsaturated alcohol stabilizer selected from the group consisting of 3-butene-2-ol, 2-butene-1-ol, 4-propene-1-ol, 1-propene-3-ol, 2-methyl-3-butene-2-ol, 3-methyl-3-butene-2-ol, 3-methyl-2-butene-1-ol, 2-hexen-1-ol, 2,4-hexadiene-1-ol, and oleyl alcohol can be preferably used.

As a nitro stabilizer, at least one nitro stabilizer selected from the group consisting of aliphatic nitro compounds such as nitromethane, nitroethane, 1-nitropropropane, and 2-nitropropropane; and aromatic nitro compounds such as nitrobenzene, o-, m- or p-dinitrobenzene, o-, m- or p-nitrotoluene, dimethylnitrobenzene, m-nitroacetophenone, o-, m- or p-nitrophenol, o-nitroanisole, m-nitroanisole, and p-nitroanisole, can b preferably used.

As an amine stabilizer, at least one amine stabilizer selected from the group consisting of pentylamine, hexylamine, diisopropylamine, diisobutylamine, di-n-propylamine, diallylamine, N-methylaniline, pyridine, morpholine, N-methylmorpholine, triallylamine, allylamine, α-methylbenzylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, dipropylamine, tripropylamine, butylamine, isobutylamine, dibutylamine, tributylamine, dibentylamine tribentylamine, 2-ethylhexylamine, aniline, N,N-dimethylaniline, N,N-diethylaniline ethylenediamine, propylenediamine, diethylenediamine, tetraethylenepentamine, benzylamine, dibenzylamine, diphenylamine, and diethylhydroxylamine can be preferably used.

As a phenolic stabilizer, at least one phenolic stabilizer selected from the group consisting of 2,6-ditertiary-butyl-4-methylphenol, 3-cresol, phenol, 1,2-benzenediol, 2-isopropyl-5-methylphenol, and 2-methoxyphenol can be preferably, used.

As an epoxy stabilizer, at least one epoxy stabilizer selected from the group consisting of butylene oxide, 1,2-propylene oxide, 1,2-butylene oxide, butyl glycidyl ether, diethylene glycol diglycidyl ether, and 1,2-epoxy-3-phenoxypropane can be preferably used.

As other stabilizers, at least one stabilizer selected from the group consisting of butylhydroxytoluene, butylhydroxyanisole, 2-propanol, and α-pinene can be preferably used.

The stabilizer is preferably at least one stabilizer selected from the group consisting of hydroquinone stabilizers, unsaturated alcohol stabilizers, nitro stabilizers, amine stabilizers, phenol stabilizers, and epoxy stabilizers; preferably at least one hydroquinone stabilizer selected from the group consisting of hydroquinone monomethyl ether (MEHQ), methoxyhydroquinone, and methylhydroquinone; and more preferably hydroquinone monomethyl ether (MEHQ).

The amount (content) of the stabilizer used is preferably about 10 ppm to 50,000 ppm, more preferably about 20 ppm to 1,000 ppm, even more preferably about 30 ppm to 500 ppm, and particularly preferably about 80 ppm to 115 ppm, as a weight ratio of the stabilizer to the above chlorine-containing compound (starting material compound).

Using the stabilizer in the above range prevents the decomposition of the chlorine-containing compound, such as HCC-140 and HCO-1130 (E/Z), as a starting material, extends the catalyst life when a catalyst is used, and prevents the formation of by-products, which allows the production of HCFC-142 with high yield and high efficiency.

(3) Fluorination Reaction

The production method of the present disclosure is characterized in that the method comprises bringing the above chlorine-containing compound into contact with hydrogen fluoride to perform at least one fluorination reactions, thereby obtaining reaction gas containing HCFC-142, hydrogen chloride, and hydrogen fluoride.

The at least one fluorination reaction performed with hydrogen fluoride may be a gas-phase reaction or a liquid-phase reaction. The fluorination reaction that is performed until HCFC-142 is obtained may be one fluorination reaction or two or more fluorination reactions, depending on the chlorine-containing compound for use.

In the present disclosure, unless otherwise specified, the pressure is a gauge pressure.

(3-1) Gas-Phase Reaction

In the production method of the present disclosure, the fluorination reaction is preferably performed in a gas phase.

In the case of a gas-phase reaction, it is sufficient if the chlorine-containing compound and the hydrogen fluoride both in their gas form come into contact with each other within the reaction temperature range described later. The chlorine-containing compound may be in liquid form when being supplied.

For example, a chlorine-containing compound in liquid form at room temperature under ordinary pressure is vaporized with a vaporizer, then allowed to pass through a preheating regio, and supplied to a mixing region in which the chlorine-containing compound is brought into contact with hydrogen fluoride, thereby performing a reaction in a gas phase. Alternatively, a chlorine-containing compound in liquid form may be supplied to a reactor, and vaporized when the chlorine-containing compound has reached a region within which the compound is reactive with the hydrogen fluoride to cause a reaction.

The hydrogen fluoride for use is preferably anhydrous hydrogen fluoride (hydrofluoric acid, hydrogen fluoride, HF), from the standpoint of suppressing the corrosion of the reactor or the degradation of the catalyst.

The method for vaporizing a chlorine-containing compound in a reaction region can be any method, and may be selected from a wide range of known methods. For example, the following method may be used. A reaction tube is filled with a material that is excellent in heat conductance, has no catalytic activity in a fluorination reaction, and is stable against hydrogen fluoride, such as nickel beads and Hastelloy pieces. The temperature distribution inside the reaction tube is then made uniform, and the reaction tube is heated to a temperature equal to or higher than the vaporization temperature of the chlorine-containing compound. The chlorine-containing compound in liquid form is supplied to the reactor tube and vaporized so as to transform it into a gas phase.

The method for supplying hydrogen fluoride to a reactor can be any method. For example, hydrogen fluoride in a gas phase can be supplied to a reactor together with a chlorine-containing compound.

Molar Ratio of Hydrogen Fluoride Relative to Chlorine-Containing Compound

In the production method of the present disclosure, the molar ratio of the hydrogen fluoride to the chlorine-containing compound (1 mol) in the fluorination reaction is preferably 1 or more, more preferably 5 or more, and still more preferably 10 or more. The upper limit of the molar ratio is, although not limited to his, preferably about 60 from the standpoint of energy costs and productivity.

A molar ratio within these ranges enables both the chlorine-containing compound conversion and/or HCFC-142 selectivity to be maintained within a more efficient (excellent) range than with conventional methods.

In the present specification, “conversion” refers to the proportion (mol %) of the total mol of compounds other than the (chlorine-containing) compounds (starting material compounds) described above contained in outflow gas (i.e., reaction gas) coming from the outlet of the reactor relative to the mol of the chlorine-containing compound (starting material compound) supplied to the reactor.

In the present specification, “selectivity” refers to the proportion (mol %) of the mol of the target compound (HCFC-142) contained in outflow gas (i.e., reaction gas) coming from the outlet of the reactor relative to the total mol of the compounds other than the chlorine-containing compounds (starting material compounds) described above.